For neurosurgical interventions the patient is positioned on a patient support apparatus, especially an operating table apparatus. In this procedure the patient is positioned on a transfer plate, since frequently during an interruption to the neurosurgical intervention and/or after the ending of the neurosurgical intervention, a medical imaging examination, for example a magnetic resonance examination of the head region of the patient, is carried out. In such cases the patient is switched by means of the transfer plate between the operating table and a further patient support apparatus, which is especially embodied as magnetic resonance-compatible for a magnetic resonance examination. For the neurosurgical intervention a surgical head restraint unit is attached to the patient, especially to the patient's head, or the patient's head is positioned within this surgical head restraint unit, wherein the surgical head restraint unit is for example disposed on the transfer plate and projects, together with the patient's head, beyond the transfer plate.
A maximum permissible residence area or positioning area is available for the surgical head restraint unit, which is especially dimensioned in accordance with a cross-sectional surface of a patient receiving area of the medical imaging apparatus. If the surgical head restraint unit projects beyond the maximum allowable positioning area for the surgical head restraint unit this can lead, during an introduction of the patient positioned on the transfer plate together with the surgical head restraint unit into the patient receiving area, to undesired collisions, especially with a housing of the medical imaging apparatus. This increases the risk of injury for the patient. In addition the surgical head restraint unit must be repositioned to enable any medical imaging examination at all to be performed. This repositioning can lead to undesired delays, since a sterile cover of the surgical head restraint unit first has to be dismantled for the repositioning.
The positioning of the surgical head restraint unit and/or of the patient's head is carried out by a surgeon and/or clinical operating personnel, wherein this positioning is very complex. In addition this positioning is undertaken on the basis of a rough estimation of the maximum permissible positioning area and/or in accordance with empirical values of the surgeon and/or of the operator. This can lead however to only a fraction of the maximum permissible positioning area being used or can still lead to collisions during the insertion into the medical imaging apparatus for instance.